package NewCoder;

import java.util.HashMap;
import java.util.Map;

public class BM53 {
    public int minNumberDisappeared (int[] nums) {
        // write code here
        int n=nums.length;
        Map<Integer,Integer> map=new HashMap<>();
        for(int i=0;i<n;i++){
            map.put(nums[i],1);
        }
        int res=1;
        while(map.containsKey(res)){
            res++;
        }
        return res;
    }
}
